The present invention relates to an arrangement for positioning a device for closing and opening a pressure vessel with use of screws, such as a steam generator.
Arrangements for positioning devices for closing and opening pressure vessels are known in the art. Known arrangements for positioning screw tightening devices or access covers possess, however, some disadvantages. These disadvantages are connected with the fact that the exact positioning encounters some difficulties because of the "wandering" of the pressure vessel as a result of its thermal expansion, within the range of between 40 and 60 mm. In order to attach the screw tightening device or the access cover to the pressure vessel after such "wandering", it is necessary in the known positioning systems to perform an adjustment before each attaching step.